JPS6024309Y2 - sewing machine threading device - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a threading device for a sewing machine, which is supported by a needle bar support and can be operated to thread a needle.

This type of threading device is known as
There are those shown in No. 6512 and Utility Model Application Publication No. 55-37013.

According to the former device, threading the needle is performed by keeping the needle bar 1 at the top dead center, pressing down the operation button 2 to lower the hook 3, and then using the operation crank 4 pivoted on the operation button 2. Claw part 4
After A engages with the needle bar holder 5, while the operation button 2 is still pressed down until it touches the stopper 6, the operation crank 4 pivots, rotates the threading finger 7, and threads the hook 3 into the needle. This is done by fitting it into the hole 8 (first A, B
(see figure).

However, this device had the following drawbacks.

One of them is to adjust the timing of the hook tip and needle hole when assembling or repairing the sewing machine, or if it is necessary to do so, move the needle bar up and down to adjust the installation position of the needle bar holder. Therefore, the distance h1 between the needle bar holder and the needle hole is
can be changed by adjusting the timing mentioned above, whereas the static distance between the needle bar holder and the pawl when the needle bar is at the top dead center.

is constant, that is, the descending trajectory of the hook is always constant, so if the above-mentioned interval h□ changes, a situation will occur where the hook cannot be inserted into the needle hole. Regarding this, if the settings are made so that threading can be performed when the needle bar is at the top dead center, even though the needle bar holder is otherwise lowered and the distance does not change. The problem is that the distance h2 increases and threading cannot be performed.

On the other hand, the latter device solves the above problems, but
To align the threading hook to the needle hole, press down on the operating part against the spring, and adjust the mounting position of the locking body while the guide pin is in contact with the locking body attached to the needle bar. If
It is not easy to adjust the position of the locking body by pushing down the operation part with one hand and pressing the guide pin against the locking body, and then loosening and re-tightening the screws with the other hand, and the pin may not lock. The more strongly it is pressed against the stopper, the more difficult it is to position it, and the more likely it is to shift downward when retightening the screw.

When adjusting the installation position of the guide pin with respect to the operating shaft, you must press down on the operating unit and move the operating shaft up and down with the guide pin against the locking body, then tighten the screw. It is not easy for one person to hold and screw the operating shaft while holding down the operating section in a limited space, and in this case too, the operating shaft tends to slide down when tightening the screws.

As described above, this device has the disadvantage that it is difficult to adjust the threading hook and it is difficult to accurately align the threading hook.

This idea was made with the aim of solving the above problem, and even if the needle bar is adjusted to adjust the timing with the tip of the needle, threading can be done reliably regardless of the position of the needle bar. In addition, the threading hook can be easily adjusted.

To explain this with the help of drawings, reference numeral 11 in the figure is a needle bar support whose upper end is pivoted to the sewing machine frame, and the needle stock 1 at its lower end.
A needle bar 15 having a needle 14 fixed to the needle 3 is pivotally supported so as to be slidable in the vertical direction. It is designed so that it can be moved up and down from an upper shaft (not shown).

The needle bar support 11 is also equipped on its side with a threading device according to the present invention, which is comprised mainly of three press-formed members: an outer member 18, an intermediate member 19, and an inner member 20. The following will be explained in order with reference to .

The outer member 18 has a vertical groove 21 in the upper part, a vertical groove 22 of the same size as the vertical groove 21 in the lower part, and 11! The grooves 23 are arranged in parallel, and the vertical groove 2
The needle bar support 11 is supported by stepped screws 24 and 24 fixed to the needle bar support 11 through 1 and 22 so as to be slidable in the longitudinal direction by an appropriate amount.

An adjustment bolt 2 whose position can be adjusted in the vertical direction descends into the bent portion 25 at the upper end and engages with the upper end surface of the needle bar when threading.
7 is screwed on.

Next, the intermediate member 19 is attached to the outer member 18 and the intermediate member 19 so as to be slidable only in the longitudinal direction by guide portions 28 and 29 provided on both the outer member 18 and the intermediate member 19 so as to be joined to the other side end surface. In addition, the operating portion 3D is bent at the lower end and the actuating portion 31 is bent at the upper end, and short vertical grooves 32 are formed at locations corresponding to the vertical grooves 23.

Further, the inner member 20 is provided with a hook 34 at the lower part, and has a bent locking part 35 at the upper part that engages with the actuating part 31 of the intermediate member from below, and furthermore, the longitudinal groove 23 of the outer member
A stepped pin 36 that loosely fits into the longitudinal groove 32 of the intermediate member is fixedly provided.

Reference numeral 38 denotes a spring that urges the inner member 20 upward, so that the stepped pin 36 comes into contact with the upper end surface of the vertical groove 23 and pushes up the outer member 18, and the member 18 is pushed up by the stepped screws 24, 24.
The lower ends of the vertical grooves 21 and 22 abut against each other, thereby being held at the upper limit position.

The spring 38 also has the function of biasing the inner member 20 about the stepped pin 36 in a clockwise direction as shown in the figure.

A spring 37 is hung between the operating part 30 and the inner member 20 and urges the intermediate member 19 upward, and is formed stronger than the spring 38, so that the lower end of the vertical groove 32 is always pressed against the stepped pin 36. At the same time, when the operating portion 30 is pressed down, the inner member 20 is lowered together with the intermediate member 19 against the action of the spring 38.

Note that the spring 37 is such that when the locking portion 35 is in the normal state, the actuating portion 3
1 to push up the intermediate member 19, this can be omitted.

If the operating section 30 is pushed down against the action of the spring 37, the operating section 31 will push down the locking section 35, causing the inner member 20 to descend, and at the same time, the outer member 18 will also move due to its own weight or the intermediate member. 19 is followed by friction with the pawl 39 that comes into elastic contact with the side end surface of the outer member, and descends until the lower end of the adjusting bolt 27 touches the upper end surface of the needle bar.

As mentioned above, the descent of the outer member is sufficiently prevented by its own weight or by friction with the intermediate member or the pawl, but in order to ensure even more It is preferable to provide a tapered single step portion 40 so that the pawl 39 pushes down the step portion.

Next, threading by this device will be explained based on FIG. 4 and FIGS. 5A to 5C.

Threading is performed by raising the needle bar 15 to an arbitrary position near the top dead center and pushing down the operating section 30 against the spring 38. When pressed down, initially, the outer member 18, intermediate member 19, and inner member 20 descend together as described above, and when the adjustment bolt 27 touches the upper end of the needle bar, only the outer member falls. stops its descent (5A
figure).

The intermediate member 19 and the inner member 20 continue to descend as one, and stop when the stepped pin 36 touches the lower end surface of the vertical groove 23 (FIG. 5B).

After that, when the operating part 30 is pressed down again, only the intermediate member 19 moves down against the spring 37 until the upper end surface of the vertical groove 32 contacts the stepped pin 36, and the pin 36 contacts the lower end surface of the vertical groove 23. The inner member 20, which is prevented from descending, is moved to the stepped pin 36 by the actuating part 31 pushing down the locking part 35.
The hook 34 is pivoted counterclockwise against the spring 38 using the fulcrum as a fulcrum, and the hook 34 is inserted into the needle hole 41 (FIG. 5C).

As mentioned above, without providing the spring 37, the locking portion 35 is
As shown in Fig. A, in the case of a type that engages with the actuating portion 31 from the beginning, the pin 36 touches the lower end surface of the vertical groove 23 and stops the inner member 20 (Fig. 6B), and then further operation is performed. The same thing as described above is performed by pushing down the portion 30 and lowering only the intermediate member 19 until the upper end surface of the vertical groove 32 touches the pin 36.

Thereafter, when the pressing force on the operating portion 30 is released, the respective members immediately move back due to the action of the springs 38 and 37, resulting in the state shown in FIG. 4.

When assembling, etc., the positioning of the hook needle in the needle hole is performed by rotating the adjustment bolt 27 while pressing down the operating portion 30 against the spring.

That is, when the amount of protrusion from the bent portion 25 is adjusted by rotating the adjustment bolt, the outer member 18 moves up and down, and the inner member 20 moves up and down via the stepped pin 36 that engages with the lower end of the vertical groove 23. It becomes like this.

As described above, this device positions the outer member by bringing the adjusting bolt into contact with the upper end of the needle bar, no matter where the needle bar is, and after the stepped pin descends a certain amount from there, the intermediate member is moved to the vertical groove 3. After the outer member is positioned as described above, the hook needle always traces the same trajectory, and the distance between the top end of the needle bar and the needle hole remains constant and changes. Therefore, even if the attachment position of the needle bar is adjusted when assembling or repairing the sewing machine, or even if the needle bar is not in the specified position, the hook needle will always pass through the needle hole and threading can be performed.

In addition, with this device, when aligning the grappling needle to the needle hole, the adjustment bolt can be rotated while holding down the operating section, and there is no problem whether the operating section is pressed strongly or weakly. Adjustment work is easy and can be done reliably.

[Brief explanation of the drawing]

Figures 1A and B are front views of the conventional example, Figures 2 to 5 show the threading device according to the present invention, Figure 2 is a front view, Figure 3 is an exploded perspective view, and Figure 4 is a side view. Figures 5A to 5C are side views showing the operation process of the operating section, and Figures 6A and 6B are side views showing the operation process of another embodiment. 11...Needle bar support, 15...Needle bar, 18...Outer member, 19...Intermediate member, 20...Inner member , 21.22.23...
...Vertical groove, 24...Stepped screw, 27...
...Adjustment bolt, 30...Operation unit, 31...
... Actuating part, 32 ... Vertical groove, 34 ...
...Crochet hook, 35...Lock part, 36...
Stepped pin, 37, 38... Spring.

Claims (1)

[Claims for Utility Model Registration] 1. Supported by the needle bar support 11 so as to be slidable in the vertical direction, always biased upward by the action of a spring 38, and a mounting portion extending laterally. An adjusting bolt 27 is screwed onto the member 25, which protrudes downward, and a member 18 that comes into contact with the upper end surface of the needle bar when descending, and the spring 3.
8 urges the operating section 30 upward together with the member 18.
The actuation mechanism of the hook 34 includes a push-down of the operating portion 30 against a spring 38 to cause the member 18 to follow and descend, and the lower end of the adjustment bolt 27 comes into contact with the upper end surface of the needle bar, causing the above-mentioned member to fall. After the descent of 18 has stopped, the hook 34
A sewing machine threading device that is constructed so that it always moves along a constant trajectory. 2. The actuation mechanism is supported by the first member 18 so as to be slidable only in the vertical direction, and includes a second member 19 which has an operation part 30 and an actuation part 31 projecting laterally, and the first member 18.
The first member is slidably and pivotally supported by a stepped pin 36 that loosely fits into the long vertical groove 23 of the second member and the short vertical groove 32 of the second member. The stepped pin 36 is pressed against the upper end of the vertical groove to urge the member upward, while it is connected to the second member by a spring 37 stronger than the spring 38, and the lower end of the vertical groove is brought into elastic contact with the stepped pin. The third member 20 has a locking part 35 that can be engaged with the operating part from below, and a hook 34 at the bottom thereof. When the second member is pressed down by the operating part 30, the third member connected by the spring 37 descends, and the first member 18 descends due to friction or its own weight, and the upper end surface of the needle bar of the adjustment bolt 27 is lowered. By hitting the first member 18
After the stepped pin 36 stops descending, both the second member 19 and the third member 20 descend until the stepped pin 36 reaches the lower end of the vertical groove of the first member, and then the stepped pin engages with the lower end of the vertical groove. As only the second member 19 descends against the spring 37 in this state, the actuating part 31 pushes down the locking part 35 and the third member 20
A threading device for a sewing machine according to claim 1, wherein the threading device is configured to pivot about a stepped pin 36 as a fulcrum. 3. The actuation mechanism includes a second member 19 that is supported by the first member 18 so as to be slidable only in the vertical direction and has an operating portion 30 and an actuating portion 31 projecting laterally, and the first member 1
The spring 38 is slidably and pivotably supported on both members by a stepped pin 36 that loosely fits into the long vertical groove 23 of the second member 19 and the short vertical groove 32 of the second member 19. The stepped pin 36 is pressed against the upper end of the vertical groove to urge the member upwardly, while the locking portion 33 protruding laterally is attached to the operating portion of the second member downwardly. and a third member 20 that is more engaged with the third member 20 and has a hook 34 at the lower part, and the operating portion 3
When the second member is pushed down by 0, the locking part 35 is placed in the actuating part 31, the third member descends, and the first member 1
8 is lowered due to friction or its own weight, and after the first member 18 stops lowering due to the adjustment bolt 27 hitting the upper end surface of the needle bar, the stepped pin 36 is attached to the lower end of the longitudinal groove of the first member. The second member 19 and the third member 20 are both lowered until the stepped pin is engaged with the lower end of the vertical groove, and only the second member 19 is lowered against the spring 37, so that the actuating portion 31 is lowered. The threading device for a chisel machine according to claim 1, wherein the third member 20 is pivoted about the stepped pin 36 by pressing down the locking portion 35.